This invention relates to a locking device for vehicles, particularly for vehicle doors of the type having a rotatable locking cylinder operable to control a central locking system as well as a safety locking lever.
A locking device of the construction of the above-mentioned type is known from German Patent Document DE 38 27 564 C2. The locking device described there contains a lock cylinder with a cylinder core into which a key can be non-rotatably inserted. The cylinder core is also non-rotatably connected with a revolving connection device constructed as a revolving rod which, by means of its end facing away from the lock cylinder, is fitted into a two-part lock nut which is rotatably disposed on the main plate. The lock nut consists of two shell bodies which are rotatably disposed on one another and are coupled with one another by way of a free running play while forming a driving connection. For this purpose, the front shell body driven by the revolving rod has a driving cam which engages in a circle-segment-type recess of the rear output-side shell body and can be rotated in it between the recess ends. After rotating the front shell body by way of the rotation of the cylinder core and the revolving rod fixedly connected with this cylinder core, after the free-running play in the recess, the rear shell body is also rotated. On its side facing away from the lock cylinder, the rear shell body has a driving pin which engages in an oblong hole of an operating lever arm of a lock-side safety lever. As the result of the rotation of the rear shell body, the safety lever is locked or unlocked depending on the rotating direction. On the circumference of the front shell body, two trip cams are arranged which are spaced away from one another on the circumference and whose contours are scanned by a switch of the central locking system. The central locking system is in each case triggered by the cam before the rear shell body can operate the safety lever. The front shell body therefore limits its function to the triggering of the central locking system, while the rear shell body has the function of mechanically operating, after another rotation of the key, the safety lever in the case of a failure of the central locking system.
Furthermore, it is known from German Patent Document DE 39 41 086 A1 that the position of the lock nut is scanned on the circumference of a one-piece lock nut, in which case two coding segments are arranged in an axially spaced manner on the circumferential surface of the lock nut and cover partial surfaces of different sizes. In this case, the coding segments have different angular positions with respect to the circumference of the lock nut and are arranged relative to one another such that, corresponding sensors are activated or that these sensors address a central locking system in the case of a rotation of the lock nut.
It is an object of the invention to further develop a locking device of the above-mentioned type in such a manner that its construction and mounting are simplified while the operability of the locking device is ensured when it is operated mechanically as well as when the central locking system is operated.
According to preferred embodiments of the invention, this object is achieved by providing an arrangement wherein the lock nut is constructed in one piece, two stops being arranged on an end side of the lock nut facing an operating lever arm of the safety lever, said stops being spaced away from one another by an angle of rotation and projecting from the end side and by means of which the operating lever arm situated between them during the rotation of the lock nut can be operated by way of the revolving connection device for the taking-up of a locking or unlocking position of the safety lever after an idle path, and wherein two cams are provided on the circumference of the lock nut for the scanning of switches of the central locking system, which cams have a different angular position to one another with respect to the circumference of the lock nut, said cams being arranged relative to the stops in the circumferential direction such that, when the lock nut is rotated, a corresponding cam operates the respective assigned switch of the central locking system as a function of the rotating direction, before one of the stops engages in the operating lever arm of the safety lever.
Because of the one-piece construction of the lock nut, and thus the elimination of a second lock nut part, and the free-running play displaced directly to the engaging of the lock nut with the safety lever for the unlocking and locking of the locking device, its construction is considerably simplified. In this case, the switching of the central locking system and the mechanical operability of the safety lever is concentrated on a single component. This clearly not only reduces the manufacturing costs of the locking device but the mounting is also facilitated by the simple axial clipping-in of the lock nut in one direction. The mounting of the lock cylinder is also improved because only the angular position of the nut relative to the lock cylinder must be fixed. In addition, it is advantageous that the manufacturing tolerances, which add up in the case of several components, will be eliminated, so that an improved switching point precision exists for the central locking system. Furthermore, an improved stability of the mechanical drive is obtained.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.